Cationic polyether urethanes are obtained, for example, as described in German Patent No. 2,252,536, from epoxy resin/amine adducts by reaction with half-blocked diisocyanates. Austrian Patent No. 343,169 discloses the introduction of basic nitrogen groups into various base resins, e.g., epoxy resin esters, by reaction with basic monoisocyanates. The epoxy resins used in the processes of the aforesaid patents can also be modified by partial reaction with diphenols, (poly)glycols, diamines or dicarboxylic acids, with chain lengthening, as described in a number of references.
It is also known from the literature that a preferred reaction of one of the two NCO-groups of isophorone diisocyanate (IPDI) can be obtained by using various catalysts. Thus, Ono, Jones, and Pappas in The Journal of Polymer Science, Polymer Letters Edition, Volume 23, 509-515 (1985), describe how dibutyl tin dilaurate catalyzes the reaction of methanol or tert.-butanol essentially with the secondary NCO-group of IPDI. 1,4-diazabicyclo-2,2,2-octane (DABCO), as a catalyst, on the other hand shows a clear preference for the primary NCO-groups of IPDI.